数据绑定：'System.Data.DataRowView' 不包含名为 'Rating' 的属性

Question

这是我的 Html 标记

    <form runat="server">

  <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" RowStyle-BackColor="#A1DCF2" Font-Names = "Arial" Font-Size = "10pt"
HeaderStyle-BackColor="#3AC0F2" HeaderStyle-ForeColor="White" DataKeyNames="FilePath" >
<Columns>
    <asp:BoundField DataField="FileName" HeaderText="FileName" />
    <asp:TemplateField>
        <ItemTemplate>
            <object type="application/x-shockwave-flash" data='dewplayer-vol.swf?mp3=<%#Eval("FilePath") %>'
                width="240" height="20" id="dewplayer">
                <param name="wmode" value="transparent" />
                <param name="movie" value='dewplayer-vol.swf?mp3=<%#Eval("FilePath") %>' />
            </object>
        </ItemTemplate>
    </asp:TemplateField>
   <asp:TemplateField ItemStyle-HorizontalAlign="Center">
                    <ItemTemplate>
                        <asp:LinkButton ID="lnkDownload" runat="server" Text="Download" OnClick="lnkDownload_Click"></asp:LinkButton>
                    </ItemTemplate>
                </asp:TemplateField><asp:TemplateField HeaderText="Song Ratings">
        <ItemTemplate>
            <asp:Rating ID="Rating1"  OnChanged="OnRatingChanged" runat="server"
                StarCssClass="Star" WaitingStarCssClass="WaitingStar" EmptyStarCssClass="Star"
                FilledStarCssClass="FilledStar" CurrentRating='<%# Eval("Rating") %>'>
            </asp:Rating>
        </ItemTemplate>
   </asp:TemplateField></Columns></asp:GridView></form>

这是我的 aspx.cs 文件

绑定 ASP.Net GridView

            protected void Page_Load(object sender, EventArgs e)
    {




        if (!IsPostBack)
        {
            BindGridviewData();


            GridView1.DataSource = GetData("SELECT SongId, FileName, ISNULL((SELECT AVG(Rating) FROM SongRating WHERE SongId = SongTable.SongId), 0) Rating FROM SongTable");
            GridView1.DataBind();
        }


    }

    private static DataTable GetData(string query)
    {
        DataTable dt = new DataTable();
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand(query))
            {
                using (SqlDataAdapter sda = new SqlDataAdapter())
                {
                    cmd.CommandType = CommandType.Text;
                    cmd.Connection = con;
                    sda.SelectCommand = cmd;
                    sda.Fill(dt);

                }
            }
            return dt;
        }
    }

//将用户评分插入并保存到 SQL Server 数据库表

    protected void OnRatingChanged(object sender, RatingEventArgs e)
    {
        int rowIndex = ((sender as Rating).NamingContainer as GridViewRow).RowIndex;
        int songId = Convert.ToInt32(GridView1.DataKeys[rowIndex].Value);
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("INSERT INTO SongRating VALUES(@SongId, @Rating)"))
            {
                cmd.CommandType = CommandType.Text;
                cmd.Parameters.AddWithValue("@SongId", songId);
                cmd.Parameters.AddWithValue("@Rating", e.Value);
                cmd.Connection = con;
                con.Open();
                cmd.ExecuteNonQuery();
                con.Close();
            }
        }
        Response.Redirect(Request.Url.AbsoluteUri);
    }



    private void BindGridviewData()
    {
        SqlConnection con = new  SqlConnection(ConfigurationManager.ConnectionStrings["constr"].ToString());
        con.Open();
        SqlCommand cmd = new SqlCommand("select * from SongTable", con);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        con.Close();
        GridView1.DataSource = ds;
        GridView1.DataBind();

    }

错误在哪里发生我是asp.net的新手谢谢

Answer 1

嗨@abhi 你没有在你的选择列表中提到“评级”列，做这样的事情

SELECT SongId, FileName, ISNULL(AVG(Rating),0) as Rating from SongTable left 通过 SongId, FileName 加入 SongRating on SongRating.SongId = SongTable.SongId 组

希望能帮到你..

Answer 2

根据您的例外情况，它说

当web控件中指定的数据项在返回的DataRowView的schema中不存在时，就会出现上述异常。 换句话说，您使用数据绑定控件指定的列不存在于从数据库返回的数据中

所以可能在BindGridviewData方法中更改您的选择查询

select * from SongTable

对此

  SELECT SongId, FileName, ISNULL((SELECT AVG(Rating) 
FROM SongRating WHERE SongId = SongTable.SongId), 0) as  Rating FROM SongTable